<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <script type="text/javascript" src="../assets/js/vue.js"></script>
    <title>methods Option</title>
</head>
<body>
<h1>methods Option</h1>
<hr>
<div id="app">
    <p>今日温度：{{temperature}}°C</p>
    <p>穿衣建议:{{this.suggestion}}</p>
    <p>
        <button @click="add">添加温度</button>
        <button @click="reduce">减少温度</button>

    </p>
</div>

<script type="text/javascript">
    var suggestion = ['T恤短袖', '夹克长裙', '棉衣羽绒服'];
    var app = new Vue({
        el: '#app',
        data: {
            temperature: 14,
            suggestion: '夹克长裙'
        },
        methods: {
            add: function () {
                this.temperature += 5;
            },
            reduce: function () {
                this.temperature -= 5;
            }
        },
        watch: {
            temperature: function (newVal, oldVal) {
                if (newVal >= 26) {
                    this.suggestion = suggestion[0];
                } else if (newVal < 26 && newVal >= 0) {
                    this.suggestion = suggestion[1];
                } else {
                    this.suggestion = suggestion[2];
                }
            }
        }

    })
</script>
</body>
</html>